Racing Diverter Valve Pair Polished Fits Porsche 996TT 997.2TT Cayenne TTOne of the most important upgrades for the Porsche 996TT, 997. 2TT, Cayenne Turbo or Panamera Turbo is to replace the factory Bosch diverter valves. The factory valves are prone to leaking pressure under increased boost when the car has an upgraded ECU flash. As well, the factory Bosch valves will taper boost off with the diaphragm design even at stock boost levels. To help keep the boost pressure constant all the way to redline, upgrading the stock